This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Dopamine receptors are concentrated in dendritic spines of neurons, including the spine head and the postsynaptic density, where they are thought to control the excitability and synaptic properties of spines. The goal of this project is to investigate the molecular mechanisms mediating the regulation of dopamine receptor localization, trafficking, and function by PSD-95, a prototypic synaptic scaffolding protein within spines.